Light-emitting device including a dual emission panel

ABSTRACT

There is a problem in a dual emission device emitting light out of both surfaces that an image on the surface and an image on the rear surface are different from each other (either image is mirror-reversed). A dual emission device is disclosed in which either light emitted from the light-emitting device is reflected by glass including a semi-transmissive film to display on glass an image same as another image obtained also from the light-emitting device, and simultaneously, external information can be viewed through the glass. A mirror can be arranged between the dual emission device and the glass including a semitransparent film.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/898,735, filed Jul. 26, 2004, now allowed, which claims the benefitof a foreign priority application filed in Japan as Serial No.2003-285390 on Aug. 1, 2003, both of which are incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a display device including a dual emissionpanel that emits light from the both surfaces of a substrate.

2. Related Art

In recent years, research on a light-emitting device including anelectroluminescent element (hereinafter, EL element) manufactured as aself-luminous type light-emitting device has been intensified. Thelight-emitting device is also referred to as an organic EL display, oran organic light-emitting diode. Such light-emitting device has beenattracted attention as a next generation display device such as a newgeneration cellular phone or a portable digital assistant for theircharacteristics of high reaction speed, low driving voltage, low powerconsumption, and the like.

An EL element including a layer containing an organic compound(hereinafter, EL layer) as a light-emitting layer has the structure inwhich the EL layer is interposed between an anode and a cathode. Uponapplying current through the EL layer, holes and electrons arerecombined to produce excitons in the EL layer (specifically, alight-emitting layer in the EL layer), and the excitons radiate energywhile returning to the ground state. The energy is released by emittinglight. Fluorescence that occurs from the singlet excited state back downto the ground state and phosphorescence that occurs from the tripletexcited state back down to the ground state are obtainable from the ELelement.

The foregoing EL layer is composed of single compound layer or aplurality of compound layers. For example, a hole injecting layer, ahole transporting layer, a light-emitting layer, an electron injectinglayer, and an electron transporting layer are appropriately stacked toform the EL layer. Materials for forming the EL layer can be broadlydivided into two categories, low molecular materials (monomer materials)and high molecular materials (polymer materials). The low molecularmaterials are formed into a film generally by a vapor deposition device.

Light from the EL layer is emitted out of a transparent anode or atransparent cathode. Hence, the EL layer can be used as a part of alight-emitting device. In general, ITO that is a transparent electrodeis used for an anode in order to emit light out of the side of theanode. (For example, see Unexamined Patent Publication No. 5-234681.)However, a light-emitting device emitting light out of both an anode anda cathode, each of which is formed by a transparent film, has beendeveloped and attracted attention in recent years. (For example, see SID03 DIGEST pp. 104-107).

There is a problem in a light-emitting device emitting light out of bothsurfaces that an image on the surface and an image on the rear surfaceare different from each other (either image is mirror-reversed), and soerect images cannot be simultaneously seen on both surfaces.

SUMMARY OF THE INVENTION

In the view of the foregoing, it is an object of the present inventionto provide a light-emitting device by which an erect image and anexternal image can be seen simultaneously, and a light-emitting deviceby which erect images can be simultaneously seen on both surfaces of thelight-emitting device.

One aspect of the invention disclosed in the specification is a displaydevice in which an image produced by light emitted from at least onesurface of the light-emitting device including the foregoinglight-emitting element is entered into a reflective and transmissivefilm (semi-transmissive film).

Either image on one surface of the light-emitting device emitting lightout of both surfaces is an erect image and another image on anothersurface is a symmetrical reverse image. By reflecting and reversinglight emitted from one surface, the identical images can be obtainedfrom the both surfaces.

According to a display device by the invention, both images can be seenby converting a reverse image displayed on one surface of thelight-emitting device into an erect image by an optical system.

These and other objects, features and advantages of the presentinvention will become more apparent upon reading of the followingdetailed description along with the accompanied drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view for showing Embodiment according to the presentinvention;

FIG. 2 is a view for showing Example 1 according to the invention;

FIGS. 3A to 3C are views for showing Example 1 according to theinvention;

FIGS. 4A to 4C are views for showing Example 1 according to theinvention;

FIGS. 5A to 5C are views for showing Example 3 according to theinvention;

FIG. 6 is an explanatory view for a light-emitting device capable ofutilizing the invention; and

FIGS. 7A and 7B are views for showing Example 2 according to theinvention.

DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of the present invention is explained.

FIG. 1 shows an example of a display device according to the presentinvention. The display device comprises a light-emitting device 21, anoptical device 22, a semi-transmissive film 23, and a support 24.

The light-emitting device 21 is a dual emission device emitting lightout of both surfaces. Accordingly, images can be obtained from bothsurfaces of the light-emitting device 21. An erect image can be obtainedfrom one surface (left side in FIG. 1) of the light-emitting device 21.A reverse image, which is obtained by mirror-reversing the erect image,can be obtained from another surface (right side in FIG. 1) of thelight-emitting device 21. Further, it is possible that thelight-emitting device 21 can be a non-transmissive dual emission displaydevice by pasting polarizing plate onto the both surfaces of thelight-emitting device 21.

A reverse image displayed by the light-emitting device 21 is captured bythe optical device 22. In addition, the optical device 22 can vary thesize of the image or correct color in the image by adjusting an opticalpath or an optical path length. The reverse image captured by theoptical device 22 is entered into the support 24, which is transparent.A semi-transmissive film 23 is provided over the surface of the support24. Consequently, the reverse image reflected by the semi-transmissivefilm 23 is mirror-reversed again to be displayed as an erect image.Further, as the support 24, which is transparent, glass, quartz,plastic, or the like can be used. According to the structure, acomposite image of both of an external image visible through the support24 and an erect image obtained by reversing again the reverse image canbe seen.

The semi-transmissive film 23 is used in Embodiment. Alternatively, areflecting film (mirror), which does not transmit light, can be used. Inthis case, the support 24 is not necessarily transparent.

In case that an erect image and a reverse image are respectivelydisplayed by both surfaces of a light-emitting device, the both imagescan be displayed as erect images by using the foregoing display deviceaccording to the invention.

Hereinafter, the invention will be explained by using examples indetail.

Example 1

In Example 1, a specific example of a display device explained inEmbodiment is explained with reference to FIGS. 2 to 4C.

FIG. 2 shows an example in which a front glass is used in a vehicle as adisplay device. FIG. 2 is an internal view of a vehicle. Referencenumeral 2000 denotes a handle; 2001, a front glass; 2007, an interior;and 2008, operation buttons. A display device according to the inventionis provided to the interior 2007. Images are displayed on screens of adisplay portion A 2002, a display portion B 2003, a display portion C2004, a display portion D 2005, and a display portion E 2006. Further,the front glass 2001 corresponds to the support 24 described inEmbodiment.

A light-emitting device included in the interior 2007 is a dual emissiondevice. The dual emission device and the front glass 2001 compose thestructure explained in Embodiment. A light-emitting device is capable ofdual emission. Light emitted from the opposite side of a driver isdisplayed on at least either the display portion A 2002 or the displayportion B 2003 of the front glass 2001. A portion displaying an image inthe front glass 2001 is provided with a semi-transmissive film in orderto view the outside of the vehicle through the front glass 2001.Simultaneously, the same display image as that displayed on the interior2007 can be viewed on the front glass 2001. By the display deviceaccording to the invention, images can be displayed on the displayportion C 2004, the display portion D 2005, and the display portion E2006, and simultaneously, images can be displayed on at least either thedisplay portion A 2002 or the display portion B 2003 of the front glass2001 to give the information similarly to that obtained from the displayportions D, E and F to a driver and people in the vehicle.

As contents displayed on the display portions A 2002 to E 2006 of theinterior and the front glass 2001, images of vehicle navigation fordriving directions for a driver, and information of speed meter or clockcan be displayed. A user operates the display screen by the operationbuttons 2008.

FIG. 3A is a top view of a vehicle, FIG. 3B is a side view of a frontface of the vehicle, and FIG. 3C is a side view of a rear face of thevehicle. In FIGS. 3A to 3C, reference numeral 2102 denotes a frontglass; 2103 a to 2103 d, cameras; 2104 a and 2104 b, sensors; 2105 a and2105 b, lights; 2106, a bumper; 2107, a wheel; 2109, a CPU; 2110, adriver; and 2111, a rear window glass. Though not shown, the vehicle hasan energy source such as electricity or gasoline, a motor for supplyingpower such as engine, a power transmission device, a brake system, asteering device, a suspension device, an electrical system, accessories,and the like. Further, the number of and the installation site of thecamera, the sensor, microphones, and the like are not restrictive asshown in FIGS. 3A to 3C, and can be determined randomly.

In FIGS. 3A to 3C, a light-emitting device according to the inventionexplained in Embodiment is realized by using at least either the frontglass 2102 or the rear window glass 2111 that is a window at a rearside. The front glass 2102 and the rear window glass 2111, each of whichdisplays an image, correspond to the support 24 explained in Embodiment.Portions for displaying images in the front glass 2102 and the rearwindow glass 2111 are provided with the semi-transmissive film 23. Alight-emitting device according to the invention can display an imagewithout hindering vision since the front glass 2102 and the rear windowglass 2111, each of which displays an image, have light-transmittingproperties and a function of displaying images. Therefore, the vehiclehas further high functionality and high added values.

A light-emitting device according to the invention does not hinder theview of a driver since the front glass 2102 and the rear window glass2111, each of which displays an image, in a vehicle havelight-transmitting properties. Accordingly, images of clock or speedmeter can be displayed on the front glass 2102 as well as the displayportion A 2101. The contents for displaying may be preferably operated,and display or nondisplay may be preferably switched by a driver withoperation buttons as appropriate.

As shown in FIGS. 3A to 3C, the sensors 2104 a and 2104 b, and thecameras 2103 a to 2103 d may be provided, and information obtained fromthem may be displayed on the front glass 2102 and the rear glass window2111 in the vehicle. Information detected by a detector for detectingexternal information of these vehicles may be displayed on the frontglass 2102 and the rear window glass 2111 in a vehicle. Additionally,the detected external information may be made a sound by an internalspeaker mounted on the vehicle for warning the driver or people aroundthe vehicle that there is danger. Accordingly, a CPU 2109 is preferablyprovided to the internal of a vehicle. All necessary components may beconnected to the CPU 2109.

In case that the sensor 2104 a or the sensor 2104 b detects an obstacle,the information on the obstacle is provided to the CPU 2109, and thewarning of the obstacle is given by the display portions A 2101 and B2108. Consequently, safer driving can be ensured. In addition, thecamera 2103 a to 2103 d may take an image of external obstacles or thestate of a vehicle to inform danger to a driver or people around thevehicle by the display portion A 2101 or the display portion B 2108. Asnoted above, a vehicle provided with a light-emitting device accordingto the invention has high added values by which a driver can drivesafely and comfortably for him or her and people around the vehicle.

As examples of vehicles manufactured by practicing the invention, inaddition to a car illustrated in FIGS. 3A to 3C, an automobile such as asports car, a track, a bus, a station wagon, a vehicle for special use(ex., an ambulance), a vehicle for special purpose (ex., a tractor), ora specially-equipped vehicle (ex., a tanker), a train, a motor cycle,and the like can be nominated. FIGS. 4A to 4C shows the examples of theforegoing vehicles.

FIG. 4A shows a bus comprising a camera 2002, a sensor 2003, a light2004, a wheel 2005, and a front glass 2006, and the like. The frontglass 2006 serves as the semi-transmissive film 23 and the support 24illustrated in FIG. 1. A display portion A 2000 and a display portion B2001 can display information from, for example, a car navigation system.

FIG. 4B shows a sports car comprising a camera 2012, a sensor 2013, alight 2014, and a wheel 2015. A front glass 2017 serves as thesemi-transmissive film 23 and the support 24 illustrated in FIG. 1. Adisplay portion A 2010 can display information from, for example, a carnavigation system.

FIG. 4C shows a train comprising a camera 2024, a sensor 2023, a light2026, and a wheel 2025. A front glass 2028 and a window glass of avehicle for carrying a passenger and the like serve as thesemi-transmissive film 23 and the support 24 illustrated in FIG. 1. Adisplay portion A 2021 and a display portion B 2022 can display, forexample, information from a centralized control room or an image forentertaining passengers.

As noted above, since a display portion in a light-emitting deviceaccording to the invention has light-transmitting properties and afunction of displaying an image, the outside can be viewed in case thata display portion is provided to a front glass or a window glass of aside face of a vehicle. Therefore, people in the vehicle and the likecan obtain further more information.

It is beneficial that the present invention is practiced so that adisplay portion is provided to a front glass as this example to be usedas a car navigation system. The car navigation system is a device bywhich information on the actual location and the direction of movementof the moving vehicle is measured by utilizing satellites, ageomagnetometer, a trochometer, and the like, and the information isdisplayed on the screen in the vehicle to inform a driver. Accordingly,a driver utilizes a car navigation system, mostly during driving.However, most screens in the conventional car navigation system arearranged below a front glass, and so there is danger that a driver takeshis eyes from a forward direction. According to the invention, a drivercan obtain information from the screen of a car navigation system whileseeing people in a forward direction or a road condition. Therefore,safe, convenient, and comfortable driving can be ensured.

In a display device explained in this example, it is also possible thatan erect image directly obtained from the light-emitting device 21 isused in the dark, and a reverse image obtained from the light-emittingdevice 21 can be switched into an erect image in the light. Accordingly,it can be prevented from making it hard to adjust eye to the outside dueto the image displayed on a front glass 23 in the dark such as night,and so visibility for an external image of a vehicle is improved.

A light-emitting device according to the invention can be freelyprovided to any part of a vehicle such as a window glass at side faces,a window glass at a roof referred to as a sun roof, and the like,besides a front glass and a rear window glass.

Example 2

An example of a structure in which a reverse image from a light-emittingdevice 21 is projected on a semi-transmissive film 23 via one opticaldevice 22 is explained in Example 1. Alternatively, a structure in whicha plurality of optical devices such as mirrors is sandwiched between thelight-emitting device and the semi-transmissive film can be adopted. Thestructure is explained hereinafter with reference to FIGS. 7A and 7B.

FIG. 7A shows a structure in which three mirrors 72, 73, and 74 aresandwiched between a light-emitting device 71 and a semi-transmissivefilm 75. The number of mirrors is not limited to three as long as it isan odd number. Since an image obtained from one side of thelight-emitting device 71 (left side in FIG. 7A) is an erect image, andan image obtained from another side (right side in FIG. 7A) is asymmetrical reverse image, people atone side (left side in FIG. 7A) candirectly see the erect image from the light-emitting device 71. An imagefrom another side (right side in FIG. 7A) is a reverse image. Thereverse image can be converted into an erect image by reflecting by themirror 72. Thereafter, the erect image becomes a reverse image again bythe mirror 73, and becomes an erect image again by the mirror 74. Theerect image is reflected on the semi-transmissive film 75. Therefore,people at another side (right side in FIG. 7A) can see the erect image.

A mirror for reducing an image is used as the mirror 72, and a mirrorfor enlarging an image is used as the mirror 74. Accordingly, a requiredoptical system can be small. Further, another device for scaling (lensor the like) can be used instead of a mirror for reflection.

FIG. 7A shows the structure in which the semi-transmissive film 75 isarranged to be in parallel with the light-emitting device 71; but notexclusively. The semi-transmissive film 75 can be provided anywhere aslong as an image is reflected on the film by changing the position ofmirrors and so on.

FIG. 7B shows a structure in which two mirrors 77 and 78 are sandwichedbetween a light-emitting device 76 and a semi-transmissive film 79. Thenumber of mirrors is not limited to two as long as it is an even number.Since an image obtained from one side of the light-emitting device 76(left side in FIG. 7B) is an erect image, and an image of another side(right side in FIG. 7B) is a symmetrical reverse image, people at oneside (left side in FIG. 7B) can directly see the erect image from thelight-emitting device 76. An image obtained from another side (rightside in FIG. 7B) is a reverse image. The reverse image can be convertedinto an erect image by reflecting by the mirror 77. Thereafter, theerect image becomes a reverse image again by the mirror 78, and thereverse image is reflected on the semi-transmissive film 79. Therefore,people at one side (left side in FIG. 7B) see the image as an erectimage.

Mirrors, lens, or the like can be used to scale an image, and asemi-transmissive film can be positioned anywhere. In this regard, it isthe same as in the case with that as mentioned above. Alternatively, areflective film (mirror) can be used instead of the semi-transmissivefilm 79.

Example 3

An EL layer in an EL element is generally formed to be a thin film tomake it easier for current to apply through the EL layer. In order toobtain uniform light emission, it is important to deposit the EL layerto have smoothness. In case that an EL layer is formed by vapordeposition over a film without smoothness, a deposited film of an ELlayer cannot cover irregularities, and pinholes are often produced. Inthis state, an anode and a cathode are susceptible to beshort-circuited, and it causes point defects in a display device.

An ITO film deposited by sputtering generally used as a transparentelectrode is difficult to be deposited to have smoothness, since the ITOfilm is susceptible to be a poly crystal and produces protrusions due tothe crystal grain growth. In case of using such the ITO film, adeposited film of an EL layer is required to be thick to coverprotrusions, and it causes the increase of a drive voltage. Further,when the EL layer becomes thick, the transmittance is reduced since themost materials for the EL layer have poor light-transmitting properties.

There is a method for polishing the ITO film in order to improve thesmoothness of the ITO film having irregularities; however, the problemis arisen that the manufacturing cost is increased, and throughput isdecreased due to the increase of the number of the manufacturingprocess.

In this example, a method for thinning the thickness to increase thetransparency of a light-emitting layer by using an anode having wellsmoothness is explained. Therefore, a light-emitting element in which ananode of an EL element is conductive polymer is explained.

As the foregoing conductive polymer, a material containing a dopantmaterial or a conductive filler for improving conductivity can be used.In addition, the conductive polymer can contain both the dopant and theconductive filler. In the structure disclosed in this example, an ITOfilm having poor smoothness is not used as an anode, and conductivepolymer having well smoothness is used as an anode. As a result, alight-emitting device with high transparency can be formed since an ELlayer can be formed to have a thin thickness. A wiring for transmittingan electrical signal to an anode formed by the foregoing conductivepolymer is formed on the anode. The wiring is preferably formed by amaterial with a high work function. Accordingly, the injection of holesto the conductive polymer is carried out smoothly, and the increase ofthe onset voltage for detectable electroluminescence can be suppressedfor the decrease of an energy barrier.

FIG. 5A is a cross-sectional view of the structure of a light-emittingelement according to the invention. A light-emitting device 1 shown inFIG. 5A is formed to have a structure in which a wiring 11, a conductivepolymer layer 12 serving as an anode, a hole transporting layer 13, alight-emitting layer 14, an electron transporting layer 15, an electroninjecting layer 16, a cathode 17 are sequentially deposited over asubstrate 10. Light is emitted out of the substrate 10 and the cathode17. In the structure, the electron injecting layer and the electrontransporting layer can be formed as one layer such as an electroninjecting transporting layer. Further, the hole transporting layer orthe electron transporting layer may serve as a light-emitting layer. Asmaterials for forming these layers, organic compounds, inorganiccompounds, or organic or inorganic mixture can be used. In addition, asused herein, the term “EL layer” is a generic term used to refer tolayers (the hole transporting layer 13, the light-emitting layer 14, theelectron transporting layer 15, the electron injecting layer 16)interposed between the conductive polymer 12 and the cathode 17.

Light emission generated in a light-emitting element can be emitted outof an anode or a cathode, or both an anode and a cathode. Hereinafter,the case that light emission is emitted out of both an anode and acathode is explained.

The substrate 10 is formed by a transparent or a semi-transmissivematerial such as glass, resin, or the like in order to emit light out ofa substrate side.

As the wiring 11 connected to the conductive polymer layer 12 serving asan anode, a material having low resistance is preferably used, forexample, aluminum (Al) or an aluminum alloy is preferably used. Inconsideration with that the conductive polymer layer 12 serving as ananode is formed on the wiring 11, the hole injection properties of thewiring 11 for the conductive polymer layer 12 serving as an anode may beimproved by forming the wiring 11 by metals, alloys, conductivecompounds, or mixture of the foregoing materials, each of which has awork function of at least approximately 4 eV, preferably, fromapproximately 4 to 7 eV. As specific examples of a material for thewiring 11, aurum, silver, copper, platinum, palladium, tungsten, nickel,or the like can be used.

The conductive polymer layer 12 is formed by a material with a high workfunction and transparency since the conductive polymer layer 12 servesas both an anode and a hole injecting layer in the invention. Forexample, a material containing mainly polyethylene dioxythiophene(PEDOT), polystyrene sulfonic acid (PSS), polythiophene (PT),polyacetylene, or a material including the foregoing substances as abasic skeleton can be used.

In the case that the conductive polymer layer 12 is formed by a materialcontaining mainly polyethylene dioxythiophene (PEDOT), polystyrenesulfonic acid (PSS), polythiophene (PT), and polyacetylene, a dopant 18may be added to improve electrical conductivity as shown in FIG. 5B. Asthe dopant, F₄-TCNQ, FeCl₃, C₆₀, iodine (I), and the like can benominated. Besides the dopant, a conductive filler 19 may be containedas shown in FIG. 5C. As the conductive filler 19, nanoparticles such asaurum, silver, platinum, palladium, nickel, carbon black, or carbonnanotubes is preferably used. The segregation of these materials isobserved at below of the conductive polymer layer 12. It seems like thatthe conductive polymer layer 12 is separated into two layers, that is, aconductive filler layer and a conductive polymer layer. Therefore, lightbecomes easy to be emitted since holes from the wiring 11 are injectedto the conductive polymer layer passing through the conductive fillerlayer.

As a material having excellent hole transportation properties for thehole transporting layer 13, aromatic trimethyl amine, a hydrazonederivative, a carbazole derivative, a triazole derivative, an imidazolederivative, an oxadiazole derivative with an amino group, polythiophene,or the like can be used.

The light-emitting layer 14 may be composed of two kinds of materials, ahost material and a dopant material. As a host material for thelight-emitting layer 14, a quinolinonato metal complex is preferablyused. As specific examples, tris-8-quinolinonato aluminum complex(Alq₃), tris-8-quinolinonato gallium complex, bis-8-quinolinonatomagnesium complex, bis-8-quinolinonato zinc complex,tris-(5-methyl)-8-quinolinonato aluminum complex,tris-(7-propyl)-8-quinolinonato complex, bis [benz{f}-8-quinolinonato]aluminum complex, or the like can be used, but not exclusively.

As the electron transporting layer 15, 8-quinolinol such as Alq₃, or anorganic metal complex including the derivative as ligands such as aquinoline derivative, an oxadiazole derivative, a perylene derivative, apyridine derivative, a quinoxaline derivative, a diphenyl quinonederivative, an nitro substituted fluorene derivative, or the like. Theelectron transporting layer may serve as a light-emitting layer. In casethat Alg₃ is used for forming the light-emitting layer, Alq₃ ispreferably used for the electron transporting layer.

As the electron injecting layer 16, a material that improves electroninjection efficiency and has excellent transparency is preferably used.Only the material may be deposited, but a material doped with an alkalimetal may be more preferably used since electron injection efficiencybecomes increased.

The cathode 17 is formed by a thin film of a material having a smallwork function such as Li, Na, Mg, Al, Ag, or In, or an alloy containingat least one of the foregoing materials, preferably, a transparentconductive film or the like such as indium tin oxide (ITO), indiumoxide, or zinc oxide. Alternatively, a film formed by a transparent orsemi-transmissive material added with Li, Cs, or the like can be used.

Though not shown, a protective film may be formed over the cathode 17.The protective film is formed by SiN, SiON, a multi-layer includingorganic materials and inorganic materials, or the like to have athickness that does not deteriorate extremely the light transmittance.These films can prevent moisture from penetrating into the EL layer toimprove the reliability.

A method for manufacturing a light-emitting element according to thisexample is explained.

The conductive polymer layer 12 is formed by coating such as spincoating or ink-jet. The dopant 18 or the filler 19 may be dispersed inthe conductive polymer layer 12. The hole transporting layer 13, thelight-emitting layer 14, the electron transporting layer 15, and anelectron injecting layer 16 are preferably formed by vacuum vapordeposition since uniform thin films can be formed by the vacuum vapordeposition. These films are preferably formed at a deposition rate offrom 0.01 to 1 nm/sec. In case that the deposition rate is too fast, aproblem may be arisen that the onset voltage is increased, the injectionefficiency of charges is deteriorated, or the like.

In the case that these layers are formed by vacuum vapor deposition,each boat filled with organic compounds is preferably individuallycontrolled its temperature to carry out co-evaporation in order to formone layer by a plurality of organic compounds. When the plurality oforganic compounds has the same or almost the same vapor pressure eachother, the organic compounds can be preliminarily mixed in one boat tobe deposited. Besides the vacuum vapor deposition, coating (spincoating, dipping, casting, or the like), Langmuir-Blodgett (LB), or thelike can be utilized.

In a light-emitting element according to this example, an anode isformed by a conductive polymer film instead of an ITO film as atransparent electrode. Accordingly, the light-emitting element hasexcellent smoothness, and a light-emitting layer can be formed to bethin. Therefore, a dual emission device having high transparency can bemanufactured. The dual emission device has an advantage thatshort-circuits due to pin-holes between electrodes, point defects, ordark spots are reduced.

A passive type light-emitting device in which a light-emitting elementis formed on a support substrate such as a glass substrate or the likecan be manufactured by using the foregoing light-emitting elementaccording to this example. Besides, an active matrix type light-emittingdevice may be manufactured in which a light-emitting element is formedover a TFT (Thin Film Transistor) array substrate, and the drive of thelight-emitting element is controlled by transistors or the like providedover the TFT array substrate can be manufactured. In FIG. 6, referencenumeral 110 denotes a substrate; 111, 112, TFTs; 113, an EL elementincluding an anode 114, an EL layer 115, and a cathode 116; and 117, awiring.

Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to beunderstood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless otherwise such changes andmodifications depart from the scope of the present invention hereinafterdescribed, they should be construed as being included therein.

1. A vehicle comprising; a car navigation system; an interior includinga light-emitting device displaying an information from the carnavigation system out of both an anode and a cathode; and a front glasswith a semi-transmissive film, wherein the information out of one of theanode and the cathode is displayed on the interior, and wherein theinformation out of the other one of the anode and the cathode isdisplayed on the semi-transmissive film.
 2. The vehicle according toclaim 1, wherein a second information of at least one of speed meter andclock is also displayed on the interior and the semi-transmissive film.3. The vehicle according to claim 1, wherein the vehicle furthercomprising a sensor detecting external information of the vehicle, andwherein a third information from the sensor is also displayed on theinterior and the semi-transmissive film.
 4. The vehicle according toclaim 1, wherein the vehicle is one of a sports car, a track, a bus, astation wagon, an track ambulance, a tractor, a tanker, a train, and amotor cycle.
 5. A vehicle comprising; a camera detecting externalinformation of the vehicle; a light-emitting device displaying aninformation from the camera out of both an anode and a cathode; and afront glass with a semi-transmissive film, wherein the information outof one of the anode and the cathode is displayed on the light-emittingdevice, and wherein the information out of one of the other of the anodeand the cathode is displayed on the semi-transmissive film.
 6. Thevehicle according to claim 5, wherein a second information of at leastone of speed meter and clock is also displayed on the interior and thelight-emitting device.
 7. The vehicle according to claim 5, wherein thevehicle further comprising a sensor detecting external information ofthe vehicle, and wherein a third information from the sensor is alsodisplayed on the light-emitting device and the semi-transmissive film.8. The vehicle according to claim 5, wherein the vehicle is one of asports car, a track, a bus, a station wagon, an ambulance, a tractor, atanker, a train, and a motor cycle.
 9. A vehicle comprising; a cameradetecting external information of the vehicle; a light-emitting devicedisplaying an information from the camera out of both an anode and acathode; and a rear window glass with a semi-transmissive film, whereinthe information out of one of the anode and the cathode is displayed onthe light-emitting device, and wherein the information out of one of theother of the anode and the cathode is displayed on the semi-transmissivefilm.
 10. The vehicle according to claim 9, wherein a second informationof at least one of speed meter and clock is also displayed on thelight-emitting device and the semi-transmissive film.
 11. The vehicleaccording to claim 9, wherein the vehicle further comprising a sensordetecting external information of the vehicle, and wherein a thirdinformation from the sensor is also displayed on the light-emittingdevice and the semi-transmissive film.
 12. The vehicle according toclaim 9, wherein the vehicle is one of a sports car, a track, a bus, astation wagon, an ambulance, a tractor, a tanker, a train, and a motorcycle.
 13. A vehicle comprising; a camera detecting external informationof the vehicle, a light-emitting device displaying an information fromthe camera out of both an anode and a cathode; a front glass with afirst semi-transmissive film; and a rear window glass with a secondsemi-transmissive film, wherein the information out of one of the anodeand the cathode is displayed on the light-emitting device, and whereinthe information out of the other one of the anode and the cathode isdisplayed on the first semi-transmissive film and the secondsemi-transmissive film.
 14. The vehicle according to claim 13, wherein asecond information of at least one of speed meter and clock is alsodisplayed on the light-emitting device, the first semi-transmissive filmand the second semi-transmissive film.
 15. The vehicle according toclaim 13, wherein the vehicle further comprising a sensor detectingexternal information of the vehicle, and wherein a third informationfrom the sensor is also displayed on the light-emitting device, thefirst semi-transmissive film and the second semi-transmissive film. 16.The vehicle according to claim 13, wherein the vehicle is one of asports car, a track, a bus, a station wagon, an ambulance, a tractor, atanker, a train, and a motor cycle.